Unable to download data from Blob storage. Getting 404 returned

Question

I'm using a Python Azure function which gets invoked when I add a blob to a storage container. The function is triggered ok, but I get a 404 response when trying to download the blob.

The blob resource definitely does exist because I can see it in the Azure portal. I've also made the container publicly accessible.

The confusing thing is that upload works fine.

def get_data_from_azure(blob_name, default=None):
try:
    azure_connection_string = os.getenv('AzureWebJobsStorage')
    container_name = os.getenv('ContainerName')
    blob_service_client = BlobServiceClient.from_connection_string(azure_connection_string)
    blob_client = blob_service_client.get_blob_client(container=container_name, blob=blob_name) 
    download_stream = blob_client.download_blob() # <----- FAILS
    data = download_stream.readall()
    return data

except:
    return default



def main(myblob: func.InputStream):
logging.info(f"Python blob trigger function processed blob \n"
             f"Name: {myblob.name}\n"
             f"Blob Size: {myblob.length} bytes")

username = myblob.name.split('/')[2]

data = get_data_from_azure(blob_name=myblob.name)

Answer 1

You can check the security settings of the Blob container, It might be that you don't have enough access rights.

In the Azure Portal Panel select

• Storage account >
• from Blob service Section Select "Blob" >
• Select Blob or Blobs that you want to change the access permission >
• Select "Access policy" >
• from the Drop Down menu select "Blob" or "Container" anonymous access based on your needs